The practice and study of cultural remains underwater. This requires an understanding of site formation processes and how materials behave when immersed. It also includes archaeological sites that are not maritime related, including plane wrecks and submerged or inundated terrestrial sites.
Traditionally, in Australia, such sites have been, and continue to be in some jurisdictions, categorised as maritime archaeology. However, since the introduction of the Underwater Cultural Heritage Act in 2018, and the increasing interest in non-shipwreck archaeology, such as inundated late Pleistocene Aboriginal sites, the term underwater archaeology is becoming increasingly used as a point of differentiation.